1. Field of the Invention
The present invention relates to a stator for an electric rotary machine which is installed in an electric vehicle or a hybrid vehicle and a fabrication method of the same stator.
2. Description of the Related Art
Conventionally, there has been known a type of stators for electric rotary machines in which coils are fabricated by winding windings around teeth of a stator core. In addition, as another type of stators for electric rotary machines, there have also been known stators in which coils are formed by inserting plural segments each made up of an electric conductor which is formed into a U-shape using segment coils in slots in a stator core, and thereafter bending leg portions and connecting end portions of the segments (refer to JP-A-2003-158840 and U.S. Pat. No. 6,894,417).
However, in such conventional electric rotary machines in which coils are fabricated by winding windings around teeth of a stator core, the windings and the stator core need to be handled separately. In addition, the winding operation becomes complex and troublesome since the windings are wound while inserting insulation papers so as to be held between the windings so wound, and there are caused fears that the insulation paper is caught between the winding wound, whereby a proper insulating performance cannot be ensured.
In addition, in the stators for electric rotary machines for vehicles described in JP-A-2003-158840 and U.S. Pat. No. 6,894,417, coils are formed through a forming operation of forming electric conductors into a U-shape, a bending operation of bending leg portions and a joining (welding) operation of joining together end portions of the electric conductors. Consequently, until the coils are formed through the joining operation, the stator core and the plural U-shaped electric conductors need to be handled separately. Further, since the U-shaped electric conductor is inserted in the slot after the insulation paper is inserted therein, there are caused fears that the electric conductor comes into contact with the insulation paper when the electric conductor is so inserted, and the insulation paper is caught between the electric conductor and the slot, whereby a proper insulating performance cannot be ensured.